1. Field of the Invention
This invention relates to a novel package for a pressurized fluid. More particularly, it relates to such a package in which a normally closed valve is attached to a necked opening of the package mechanically. Most especially, it relates to such a package in the form of a plastic syphon package for a pressurized liquid, such as seltzer water.
2. Description of the Prior Art
Syphon seltzer water was traditionally supplied in thick walled glass bottles with permanently attached dispensing heads, through which the bottles were filled with carbonated water at a sufficiently high pressure to provide enough force for dispensing all of the water from the bottle. For safety and economic reasons, the traditional syphon seltzer industry has virtually ceased to exist in the United States, although it has continued in certain other countries, most notably Argentina.
More recently, a plastic syphon seltzer bottle has been developed with a removable head. These packages are sold in supermarkets with a conventional twist off cap over a normally closed valve in the necked opening of the bottle. Such plastic syphon seltzer packages are described in the following commonly assigned issued U.S. Patents and pending application: U.S. Pat. No. 4,660,748, issued Apr. 28, 1987 to Hagan; U.S. Pat. No. 4,671,436, issued June 9, 1987 to Hagan; U.S. Pat. No. 4,694,975, issued Sept. 22, 1987 to Hagan; Application Ser. No. 07/008,628, filed Jan. 29, 1987 in the names of Richard J. Hagan and John J. McIntyre, now U.S. Pat. No. 4,773,571.
In these packages, the normally closed valve is contained in a plastic insert that is attached to the inside wall of the necked opening of the bottle by ultrasonic bonding. The ultrasonic attachment process is described in the following commonly assigned pending U.S. applications: Application Ser. No. 06/893,,041, filed Aug. 1, 1986 in the name of Richard J. Hagan, now U.S. Pat. No. 4,726,481 and Application Ser. No. 07/030,166, filed Mar. 25, 1987 in the name of Richard J. Hagan now U.S. Pat. No. 4,726,480. In practice, while the ultrasonic bonding process produces very reliable bonding of the valve insert in the necked opening, the ultrasonic bonding process has proved to be a limiting factor in the fabrication rate of the packages. Also, the packages resulting from these ultrasonic packages provide a seal that has proven to be commercially acceptable for the seltzer packages in ordinary supermarket distribution. However, should the packages be heated above about 100 degrees F. for a substantial period of time, relaxation of the plastic in the insert and the necked opening of the bottle can lead to loss of pressurization. This is ordinarily not a problem, even in a hot climate, because it takes a substantial length of time with the package exposed to temperatures above 100 degrees to elevate the package above that temperature because of the volume of water that must be heated to do so. However, it would be desirable to increase the ability of the package to maintain its pressure at elevated temperatures.
The use of ultrasonic bonding to fasten the normally closed valve insert in the necked opening of the bottle means that the bottle cannot be filled with seltzer water until after the insert has been fastened in place. Filling is then accomplished through the normally closed valve and syphon tube by inverting the bottle and opening the valve. An apparatus and process suitable for filling seltzer packages with the valve insert in place is described in U.S. Pat. No. 4,617,973, issued Oct. 21, 1986 to Hagan and Lempert.
In contrast, conventional soft drink bottles are filled with the bottles in an upright position. While the Hagan and Lempert apparatus operates very well to fill the plastic seltzer bottles, the ability to fill the bottles in an upright position would allow the use of slightly modified conventional filling equipment and provide a much higher filling rate than the Hagan and Lempert apparatus.